Gyuki is a high-ranked subordinate of the Nura Clan and one of its board members.

He is a careful and meticulous planner, and his plans always have the Nura Clan's best interests at heart. He is generally a quiet and calm person who listens to all the facts before passing judgment, and his opinion is regarded highly. Once he reaches a conclusion, he will see it through to the end.

Gyuki was once a human named Umewakamaru who was born into a house of nobles. He decided to search for his mother after his father's death and her disappearance. He was tricked by a yokai who claimed to know his mother, when in reality it had eaten her, and was eaten himself. However, through the power of his hatred and will, he was reborn as a yokai after his death, destroying the yokai that had killed his mother and himself in the process.